Extension top for desks and the like



March 15, 1932. b. E. HUNTER I EXTENSION TOP FOR DESKS AND THE LIKE I5Sheets-Sheet Filed Feb 27, 1928 D. E. HUNTER EXTENSION TOP FOR DESKS ANDTHE LIKE 3 Sheets-Sheet 2 Filed Feb. 27. 1928 m NWN March 15, 1932. D.E, HUNTER 1,849,092

EXTENSION TOP FOR DESKS AND THE LIKE Filed Feb. 27, 1928 3 Sheets-Sheet3 face of the permanent top but one which abuts edgewise 'thereagainstthus affording no break or interval between. Such an ex' tensiontherefore possesses distinct advan-- Patented Mar. 15 1932 V Inairsnfsrarss' PANY, or MusKneon, ICHIGAN, A CORPORATION OF MICHIGAN TEXTENSION TOP EOE DESKS AND 'THE' LIKE Application filed February 27,lees. serial No. 257,160. a

This invention. relates ,to improvements in extension tops for desks,and more particularly to a sliding top or shelf capable ofbeingconeealed beneath the permanent top when-not in use, and to be'withdrawn -be-- position, and when so extendeclnot only pre sents aworking surface-flush with the surtages over the ordinary type ofextension top common to desks, tables and the l1ke, which are below thepermanent top, and therefore while affording additional working area arenot so positioned'as to be'the equivalent of an extension flush withthe. permanent top;

Ma-nifestly an extension top of the character hereinafterto be describedis not limited in isdisclosed in the accompanying drawings,

in which 7 .Flgure 1 is a top plan view of the portion of a desk topbelow which the extension top is located, portions of the permanent andex-v tension'tops beingbroken away to' show the" supporting caniagebeneath, Figure 2 is-a view in vertical transverse section taken on line2' 2 of Figure 1.

Figure 3 is a view inlongitudinal vertical section through the frontedge portion of the desk taken on 'line 3-3'of Figure 2 showing theextension top in retractedposition'. Figure 4c is a view similar toFigure 3 showing the top-extended preparatory to eleva v v a rollers to.slide in ahorizontalplane inward;

tion.' 1 i Figure5 is'aviewsimilartoFigure 4 showing the top elevatedlntothe final position.

Figure 6=-is a detail view of oneof. the link connectlons between thetop section and Icar -g,

toprovide 1 Parser 0mm nnv rn n. HUNTER, or MusKEeoN, MICHIGAN,assidnonrro THE SHAW ALKER comriage of the extension top astaken on line66 of Figure 1. v m H 1Figure 'Zis a top plan view of one edge portionof a desk with extension'top and guard rail in extended position.

Figure 8'is a view in side elevation of-the extension top guard rail inextended position'.

'Fi'gure' 9"is'a view in front elevation of the-extension top and guardrailin retracted position; and

Figure 10 is a perspective view of the same] parts in partially extendedposition;

For the purposeof this disclosure, the upper portion of metal desk isshown, includmg the 'permanenttop and a. space immediately below "inwhich the extensjible top is housed. According to the usual practice,the extension top is arranged to be withdrawn forwardly and intoextendediposition at one a or bothsides of the desk, the-left side beingI illustrated herein, v

. Referring now to the construction e1nbodyingthe features of theinvention, the upper section of the desk is provided with a relativelyshallow housing over which extends the topwall 1, and surrounded onthree sides by side walls 2, 2 and a rear Wall 3, the front being opento provide an entrance slot for theexte'nsion top and from whichtheforward'edgethereof projects. The'top Wallis preferably covered witha" layer ofilinole'uin 1a or other covering material which forms the topsurface of the desk.

As is the practice in metal furniture con structiomthe frame members andwalls'of the desk are formed from blanks of sheet metal, shaped andspot-welded into a rigid structure but these details of constructionneed not be'elaborated upon; Within-the top casingis housed theextensibletop, cona fiat skeleton framemember mounted on ly andoutwardly. Theltop 'section 5 isafiat.

Zsisting of two mainlandrelativelyshiftable -members, to wit, acarriageor sliding frame 4, and the top section 5. 'Tl1ecarriage.41.1s.-

i plate mounted upon and moving with itsca 'riage, and capable ofbeingishifted vertically andqhorizontally relative ithe'reto by. 'meansioe aintil the latter clears the front edge of the desktop, and then thetop is swung vertically and horizontally to final position. Theelevating and depressing of the top section is accomplished manually bylever actuated mechanism which imparts a parallel movement to the top. 7

As shown in Figures 1 and 2, the carriage 4 consists of a pair oflongitudinal frame members 6, 6, consisting of strips of sheet metalbent into substantially S-shape (thus These frame members extend justbelow the side edges of the top section 5, and are connected together bythree parallel transverse frame members 7, two being located at the endsof the carriage and one just forwardly of the rearmost member. Thesecross members are strips of sheet metal bent into inverted U-shape (thusL their ends being mortised and spot-welded tothe longitudinal framemembers 6, 6.

The transverse frame member 7 at the extreme rear of the carriage formsa housing for a pair of pintle rods 8, 8, held in place by bolts 8a, 8a,these rods projecting from opposite sides of the carriage and carryingrollers 9, 9, at their extremities. These rollers engage track members10, 10, secured to the side walls 2, 2, of the desk and extending fromthe rear end of the extension top housing to a point just short of itsforward end.

7 These tracks are channel shape with roller engaging flanges projectinginwardly, the rollers 9, 9, being slightly less in diameter than thevertical distance between the flanges, both of which are engaged,depending on the position of the carriage and the distribution of theload.

Extending across the forward end of the extension top housing andforming the lower edges of the entrance slot thereto isa ll-shaped framemember 11 forming a part of the desk. Adjacent the ends of this framemember and in alignment with the downwardly facing channel, section 6a,6a, of the longitudinal frame members 6, 6, are mounted stationaryrollers 12, 12, journalled, in suitable roller bearings 13, 13. Theserollerssupport the forward portion of the carriage, engaging downwardlyfacing tracks formed by the channel sections 6a, 6a, of the longitudinalcarriage frame members 6, 6.

The extension top section 5 consists of a flat wall 14L covered with alayer of linoleum 15 and otherwise resembling a "rectangular sectionofthepermanent desk top. The edges of the top wall 14: are preferablysurrounded by downwardly extending flanges 14a.

As shown in Figures 1 and 3, the top section 5 is somewhatshorter thanthe carriage 4, its rear edge terminating just forwardly of theintermediate cross member 7 of the carriage some six or seven inchesfrom the rear end thereof, although its forward edge proj ects perhapstwo inches beyond the forward cross member 7 of the carriage.

The top section is mounted on the carriage by two separate-pairs ofconnecting and operating members, one adjacent its rear end and theother adjacent its front edge and the members of each pair being locatedat opposite sides of the extension top assemblyiand comprising parts asfollows: The rear pair of connecting members consists of links 16, 16,pivotally connected at one end to the carriage and at the other end tothe top section through the medium of inverted U-shaped channel members17 extending lengthwise of the underside of the top section andpositioned just inwardly from and above the longitudin al frame members6, 6, of the carriage and pintle pins 18 passing horizontally andtransversely through the depending webs of said channel members. Thesepintle pins are free to turn on their axis, being fixed to one end ofeach of the links 16. A similar pivot mounting is provided for oppositeends of the links, there being provided along the inner edge portions ofthe longitudinal carriage frame members, 7 7, angle strips 19 withupstandingflanges 19a spaced from the side of the channel portion 6a ofsaid longitudinal frame members, and in holes therein another pair ofpintle pins 20, 20, for the opposite ends of the links 16 arejournalled.

The connecting members at the front of the top section also include theoperating parts consisting of the following mechanism: Just rearwardlyof the foremost cross member 7 of the carriage frame, is a transverserod or crank shaft 21 journalled at its ends in the inner vertical wallsof the channel portion 6a of the longitudinal frame members 6, 6, of thecarriage frame (Figure 2). Fixed to the shaft 21 just inwardly from thejournalled ends thereof, are cranks 22 positioned in vertical alignmentwith the channel members 17 on the under side of the top plate 14. Atthe ends of the crank arms are transverse pins 22a which are j ournalledin holes punched in the outer depending flanges of the channel member17. Midway between the ends of the shaft 21, is fixed an operatinglever23 for turning the shaft 21 and cranks 22 and thus elevating andlowering the extension top as will now be described; reference beinglater made to the meansemployed for locking the operating lever to hold.thetop in elevated top section'4 lies fiatwise uponthe carriage.

position and for releasing the same for lowering the top. V

As is readily apparent from the foregoing. description, the position oftheextension'topwithdraw thetop from the desk, it is merely pulledoutwardly from the "front edge, the carriage 4 and top 5;moving as aunit, partly supported by the rollers 9, 9, and partly by the stationaryrollers 12, 12. When the top is extended to a position beyond the frontedge of the desk top in which its rearedge clears the same by an inch orso, its further with drawal is prevented by two stops 6band 612 securedto the longitudinal .frame members 6, 6, of the carriage and projectdownwardly for contact with the forward frame member 11 of the desk(Figure 3). f.

In the extended position (Figure 3)-the and in a depressed position.that is, with its surfacebelow that of the desk and a'space between therear edge of the top and the front edge of the desk. Moreover,theoperating lever 23 is in a position extending horizon tally from theshaft 21 and in a rearwarddirection. The top section is elevated byreaching under the top, grasping the handle 230: at the end of the-leverand pulling'downwardly and forwardly thereon. By this movement the shaft21 is rotated in a clockwise direction through at the same time rotatingthe cranks 22, 22, in a counter-clockwise direction (Figure 4) from ahorizontal forwardly extending position to a vertical position. Thismovement of the cranks carries the top section 5 upwardly and rearwardlywith a parallel movement, the links 16, 16, being the equivalents of thecranks, res ond to the force imparted to the cranks and also swing intoa vertical position. This upward and rearward swinging movement of thetop section thus simultaneouly brings the surface of the top sectioninto the plane of the desk top, and brings itsrearedge into M abuttingengagement with the front edge of In this connection it is to bethe desktop. I observed that the parallel movement of the top section is due toequality of the throw of'the cranks 21 and links 16, this .throwin turnbeing-equal to the radius of the are through which the top is swung'tobring it.

into .and out of, its elevated position;

The elevation of the top being a manual operation, additional means forholdingthe top] elevated position is required, since In the retractedposition of the exotherwise "it would I return; to its depressedposition :on the carriage .when the leveris released. :xThis meansconsists of locking 9 members acting on the lever 23 to hold the shaft21. against turning-"and comprises a we I link 24 ipivotally connectedto the lever 23,

midway of it's ends through the medium of a.

pin'25 passing.- through the link a short dis-. tance inwardly .fromitsendand'an ear 23b integral withthe lever. r

The link 24 extends'rearwardly from the lever 23 and is connected'forhorizontalslid-1' ing movement at its opposite end with a channel member26 mounted on the underside of the top wall. 14 of the top section 5approximately at its center and extending in a for; ward and rearwarddirection.- In one of the depending flanges of thechannel member26 is alongitudinal slot 26a in which the adj acent end of the link 24 slides,ashort'pin 24a forming theconnecting member. The length of the slot issuch as to accommodate the} trave-lof the pin 24a from end to end in theswinging movement of the operating lever 23 r from the downwarddepending position shown in F i ure 4 to theirearward horizontalposition of igure At the forward end of the slot 26a is adownwardly'olfset locking I notch 2 6b into which the pin24a drops whencarried forwardly by the downwardswinging movement of the lever. In thisposition the link 24 assumes the function of abrace pre venting thelever23 from. being moved in either; direction and hence holding'the topfirmly in elevated position To release the link 23 from the lockingnotch 26b sothat the top can be lowered, the handle 2300f the ice leveris grasped as before and by pressing V downwardly on the forwardlyextending end I of the link, its rear end is lifted sufiiciently' torelease the pin 24a from :thelocking notch 266 thus permitting it toslide rearwardly in the slot 26a and the top to resume its depressedposition on the carriage. Thusde-c pressed, the carriage isfree to bepushed, backwardly into its retracted position within the desk.

In order to permit adjustment of the locking membersto compensatefor'any slight variation in the assembly of the parts, the chan;

nel' member 26 is not fixed directly to the 'un-.

derside of the top but indirectlythrough an gle plate 27 having oneflange 27a spot welded tothe'wall 14, andthe otherdepending in Iflatwise contact with unslotted flange of the channel? member 26; 1Through these contacting flanges are inserted bolts 28, 28, the bolt'holes in one ofthesflangesfl (preferably those in the fixed .angleplate)being elongated so that the channel member 26 can be moved slightlyforwardly or rearwardly and thus, shift-the position of the slot26basrequired.

As anladded'featuretobe applied in con junction withan extension'topespecially: in a desk having vertically'extending walls-at the back andone or both sides thereof, is a telescopic side rail adapted to form anextension of the fixed guard rail along the corresponding side ofthedesk.

A desk provided with guard rails and an extension or telescopic guardrail is shown in Figures 6 to 9. These guard rails 29 are merelyvertical extensions of the side and rear walls projecting 2 or 3 inchesabove the top surface of the desk and are desirable in some forms ofdesks, as for instance .for bookkeeping orother special purposes toprevent papers from being dislodged and scattered. Otherwise the deskand the extension top are the same as already described. The extensionrail 30 consists of a strip of sheet metal bent into L-section andslidably mounted in a hou ing located along the angle between the top ofthe desk and the side guard rail 29, and formed by mounting a housingplate 31 of a corresponding L-shap-ed section to the inner face of theguard rail, and housing plate having 'a marginal flange 31a along itstop edge which is spot welded to the face of the guard vious; Similarlythe-extension rail is a convenient addition to the extenslon topalthough not a necessary ne.. Structural details and rail with the mainbody of the plate slightly offset so as to form a space of the samegeneral sectional contour of the extension guard rail in which thelatter can slideendwise with its horizontal web 30a flush with thesurface of the desk. At the forward end of the ext-ensionguard rail 30is a downwardly projecting pin 32 extending below the topof the desk andat one side of the top section 5 of the extension top. Fixed to the sideedge of the top section is a bracket 33 having a vertical bore 83atherethrough and into which the pin extends for free vertical slidingmovement. Thus as the extension top is with drawn from the space beneaththe desk top the extension rail is withdrawn from its housing above thedesk top. During the forward movement of the extension top, the topsection is below the level of the extension rail, but on being elevated,its side edge is brought up flush with the under side of the horizontalweb 30a of said rail 30, the latter being curved downwardly at its edgeto provide an edgewise overlapping contact. Due to the slidingengagement of the pin 32 in thebracket 33, the top section is free to beshifted vertically relative to the rail as it is elevated or depressedand yet the connection is maintained so that they slide together to andfrom re-- tracted positions in their respective housings;

The advantages of anextension top embodying the features hereindisclosed have already.

been pointed out, but otherwise would be obmechanical parts may beobviously varied without departing from the spirit of the invention, andtherefore I'do not wish to. be

limited in either of these respects.

I claim as my invention;

position of said top section.

1." An extensible top for desks and the like comprising a carriageslidably mounted in a space below the top of said desk for withdrawal toand from extended position, a top section mounted on said carriage andadapted to normally assume a position below and forwardly of the desktop in the extended position of said carriage, links connecting one endand cranks connecting the other end of said top section with said.carriage, and a lever operatively connected with said cranks to rotatethe same through a predetermined angle whereby said top section is swungupwardly and rearwardly from its position on said carriage when thelatter is extended, to bring said top section into the plane of thedesktop with its rear edge abutting the adjacent parallel edge of saiddesk top.

2. An extensible top for desks comprising a carriage slidable into andout of a space below the top of said desk,-and having rollers adjacentits rear edge, tracks fixed to said desk along the sides of said spaceand engaged by. said rollers, suporting rollers mounted onthe desk belowsaid carriage at the front ofsaid space and supporting said carriage,atop ,ection mounted on said carriage for relative displacement, linksconnecting the rear portion of said top section with said carriage,cranks connecting the front portion of said top section with saidcarriage, a shaft journalled on said carriage and connected with saidcranks, a lever mounted on said shaft, and lockingnieans interposedbetween said lever and said top section.

- 3. An extensible top for desks comprising a carriage slidable into andout of a space below the top of said desk, andhaving' rollers adjacentits rear'edge, tracks lixed to said desk along the sides of said spaceand engaged by said rollers, rollers mounted acent the front of saidspace and supporting said carriage, a top section mounted on saidcarriage and normally resting'in depressed posi' tion thereon below thelevel of the top of said desk with its rear edge spaced forwardly of theadjacent edge. of said desk top when said carriage is extended, pairs ofcranks and links journalled on said carriage and connected with theunder side of saie topsectiOn at points spaced apart lengthwise thereof,a shaft connecting said cranks, a lever mounted on said shaft and operaive to swing said cranks through a predetermined angle to effect theparallel motion cf said top section into the plane of said desk top andin abutting contactat adjacent edges, a link pivotally connected 'at oneen d with said lever, a slotted member mounted on the underside of saidtop section'and having slidable engagement with the other end of saidlink ahd a notch at one end of said slot adapted to prevent said: linkfrom sliding inthe elevated lfAn extensible top for desks comprising acarriage slidable into and out of a space below the top of said desk, atop section mounted on said carriage and normally resting in depressedvposition thereon below the levelof the top of said desk, with its rearedge spaced forwardly of the adjacent edge of said desk top when saidcarriage'is eX-' tended, pairs of cranks and links journalled on saidcarriage and connected with the under,

side of said top section at points spaced apart lengthwise thereof, ashaft connecting said cranks, a lever operatively connected with saidcranks to swing the same through a predetermined angle to effect theparallel motion of said top section into the plane of said desk top andin abutting contact at adjacent edges, a link pivotally connected at oneend with said lever, a guide member mounted on the underside of said topsection and having a slot slidably engaged by the other end of said linkand a notch at one end of said slot adapted to lock said link againstsliding for locking said lever in the elevated position of.

said top section, and to be released therefrom vto permit said topsection to be depressed.

, 5. An extensible top for desks comprising acarriage shdable into. andout of a space below the top of said desk, an extension top sectionmounted on said carriage for displacement relative thereto, linksconnecting said top section with said carriage, a crank member mountedon said carriage and con nected with said top section, an operatinglever connected with said crank member and coacting locking members onsaid topsection and carriage and operative by said lever to lock saidtop section in extended and elevated position.

6. An evtension top for desks and the like,

comprising a carriage slidably mounted in a space beneath the top of thedesk and extensible therefrom to a position outwardly beyond and belowthe level of said desk top, a top section mounted on said carriage forvertical displacement in its extended position into and from the planeof said desk, means for normally elevating said top section, andreleasable means for supporting said top section in elevated position.

7. An extensible top for desks and the like, comprising a carriagemounted below the top of said desk for sliding movement to and from anextended position below and beyond one edge thereof, a top sectionsupported uponsaid carriage, rocking members connecting said top sectionwith said carnage including a hand actuated crank for shifting said topsection vertically andhorizontally into the plane of the desk top andinto abutting contact at their edges, andmeans for locking saidcrankintheelevated position of said top section.

Signed at Muskegon this 23 day of' Feb DAVID E. HUNTER.

ruary, 1928.

